There are two types of DM – DM1 and DM2. DM1 is caused by a repeat expansion in the DMPK gene. DM1 is a multisystem disorder that affects skeletal and smooth muscle as well as the eye, heart, endocrine system, gastrointestinal system, and central nervous system.
DM1 is very commonly associated with daytime sleepiness. It also frequently impacts the respiratory muscle and results in significant breathing problems. As DM1 progresses, the heart can develop an abnormal conduction and heart rhythm. There is currently no cure and there are no disease-modifying treatments.
There are approximately 40,000 diagnosed patients in the United States.
DM1 is driven by an expanded CUG trinucleotide repeat in the 3’-untranslated region of DMPK transcripts. These abnormal transcripts cause mis-regulated splicing for certain messenger RNAs which are directly linked to the clinical manifestations of DM1.
